Fix USB Devices Automount Not Working In Ubuntu 10.04 Lucid Lynx

It seems there's a bug in Ubuntu 10.04 Lucid Lynx which affects USB devices which do not automount when plugged-in meaning the device isn't displayed on the desktop and also doesn't show up in Nautilus.

I upgraded to Lucid a long time ago and this bug wasn't occurring but today when trying to plug in an USB device (I actually tried several devices - a music player and several USB memory sticks) they simply won't automount.